Pen



FIG. 1 is a front perspective view of a pen according to my design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is an exploded perspective view thereof showing the pen with the cap removed.

The broken lines shown in the drawings show portions of the pen that form no part of the claimed design. The dot-dash line in FIG. 8 is a boundary line that forms no part of the claimed design. 

CLAIM The ornamental design for a pen, as shown and described. 